Rotation Angle Detection Stabilization via Parameter Modification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotation angle detecting devices without magnetic flux collecting members suffer from reduced accuracy, especially near the rotation angle corresponding to the maximum magnetic force detection value, due to large variations in output voltage caused by variations in magnetic force detection values, particularly when the magnetism generating member generates less magnetism or deviates in position.
Innovation Solution
A rotation angle detecting device comprising a magnetism sensing element and a processing part that calculates and outputs an output voltage based on the magnetic force detection value using the equations V2=k×arcsin(V1/(VM+α))+Voffset or V2=k×arccos(V1/(VM+α))+Voffset, where V1, V2, VM, k, α, and Voffset represent the magnetic force detection value, output voltage, maximum magnetic force detection value, gain, and predetermined offset, respectively, to stabilize the output voltage and enhance detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If magnetic flux collecting members are omitted to simplify configuration and reduce cost, then device complexity is reduced, but measurement precision deteriorates due to large output voltage variations near maximum magnetic force detection value
Solution Approach 1:
The patent applies parameter changes by modifying the output voltage calculation parameters. Specifically, it uses V1/(VM+α) instead of V1/VM in the arcsine or arccosine function, where α is a predetermined value that prevents the denominator from being too small. This parameter modification stabilizes the output voltage near the maximum magnetic force detection value, resolving the accuracy issue while maintaining the simplified configuration without magnetic flux collecting members.
2Device complexity
If conventional arcsine or arccosine calculation is used without parameter modification, then calculation is simpler, but output voltage varies largely near maximum magnetic force detection value, reducing measurement precision
Solution Approach 1:
The patent modifies the calculation parameter by introducing α to the denominator (VM+α). This small parameter change prevents division by small numbers when V1 approaches VM, thereby stabilizing the output voltage and improving measurement precision while keeping the calculation method fundamentally the same (still using arcsine or arccosine functions).
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the influence of variations in magnetic force detection values on the output voltage, thereby improving the accuracy of rotation angle detection in a simple configuration without the need for magnetic flux collecting members.
Implementation Method 1
a magnetism sensing element provided relatively rotatable to a magnetism generating member to output a magnetic force detection value corresponding to a perpendicular component of magnetic flux applied from the magnetism generating member
Data Source
AI summary
A magnetism sensing element is provided to be rotatable relative to permanent magnets and outputs a magnetic force detection value, which corresponds to a perpendicular component of magnetic flux. A Hall IC calculates and outputs an output voltage, which corresponds to a relative rotational angle between the permanent magnets and the magnetism sensing element, based on the magnetic force detection value outputted by the magnetism sensing element. The Hall IC calculates the output voltage as V2=k×arcsin(V1/(VM+α))+Voffset, in which V1, V2, VM, k, α and Voffset indicate the magnetic force detection value, the output voltage, a maximum value of the magnetic force detection value, a gain, a predetermined value and a predetermined offset value.